I've landed cover photos and opening spreads with 4k video.You still must be able to capture at least 6k RAW video in order to really use it as a an indefinitely long burst mode of 20MP stills.
Good news is that this has been possible since May using consumer ILC cameras like Panasonic S1H
"Panasonic has announced the LUMIX S1H firmware update program version 2.1 that supports RAW video data output. Working together with Atomos, a global company that creates video equipment for professional film creators, the new firmware enables the output of maximum 5.9K/29.97p and 59.94p 4K* RAW video data over HDMI to save it as Apple ProRes RAW on the Atomos Ninja V 4K HDR monitor-recorder."
So there you go. All you need is S1H, Atomos Ninja V and a bag full of SSD disks to shoot an entire 90+ minutes soccer game in continuous 20MP 30fps burst.
You might need some time to go through all 162 000 images and select the good ones though.
(Technically speaking it's 19,5MP at 29.97fps but who cares)
I liken it to shooting with a 15 year old DSLR - you really need to nail your composition and exposure in camera because you don't have much latitude in post. And like all things, it's the content that counts the most.